<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <script src="js/react.development.js"></script>
    <script src="js/react-dom.development.js"></script>
    <script src="js/babel.js"></script>
</head>

<body>
    <div id="root"></div>
    <script type="text/babel">
        // JSX  js + xml
        let inner = (<div><h1 className="title" id="title">
            <strong>hello</strong>
            <em>React</em>
        </h1>
            <div></div>
        </div>);
        ReactDOM.render(
            inner,
            document.querySelector("#root")
        );
    </script>
</body>

</html>